Featured Research

from universities, journals, and other organizations

New order of marine creatures discovered among sea anemones

Date:

May 7, 2014

Source:

American Museum of Natural History

Summary:

A deep-water creature once thought to be one of the world's largest sea anemones, with tentacles reaching more than 6.5 feet long, actually belongs to a new order of animals. The finding is part of a new DNA-based study that presents the first tree of life for sea anemones, a group that includes more than 1,200 species.

A deep-water creature once thought to be one of the world's largest sea anemones, with tentacles reaching more than 6.5 feet long, actually belongs to a new order of animals. The finding is part of a new DNA-based study led by the American Museum of Natural History that presents the first tree of life for sea anemones, a group that includes more than 1,200 species. The report, which is published today in the journal PLOS ONE, reshapes scientists' understanding of the relationships among these poorly understood animals.

Related Articles

"The discovery of this new order of Cnidaria -- a phylum that includes jellyfish, corals, sea anemones, and their relatives -- is the equivalent to finding the first member of a group like primates or rodents," said Estefanía Rodríguez, an assistant curator in the Museum's Division of Invertebrate Zoology and the lead author of the new publication. "The difference is that most people are far more familiar with animals like chimpanzees and rats than they are with life on the ocean floor. But this amazing finding tells us that we have so much more to learn and discover in the ocean."

Rodríguez, along with an international team of researchers, conducted a four-year study to organize sea anemones in a "natural," or phylogenetic, way, based on their evolutionary relationships. Sea anemones are stinging polyps that spend most of their time attached to rocks on the sea floor or on coral reefs. Although they vary greatly in size and color, anemones have very few defining structures. As a result, classifying these animals based on morphology alone can be difficult.

"Anemones are very simple animals," Rodríguez said. "Because of this, they are grouped together by their lack of characters -- for example, the absence of a skeleton or the lack of colony-building, like you see in corals. So it wasn't a huge surprise when we began to look at their molecular data and found that the traditional classifications of anemones were wrong."

The researchers compared particular sections of DNA of more than 112 species of anemones collected from oceans around the world. Based on genetic data and the organization of their internal structures, the scientists reduced the sub-orders of anemones from four to two.

They also discovered that one of species that they analyzed is not a sea anemone at all. This animal, previously called Boloceroides daphneae, was discovered in 2006 in the deep east Pacific Ocean and labeled as one of the largest sea anemones in existence. But the new study shifts it outside of the tree of life for anemones. Instead, the researchers placed it in a newly created order -- a classification equal to carnivoria in mammals or crocodilia in reptiles -- under the sub-class Hexacorallia, which includes stony corals, anemones, and black corals. The new name of the animal, which lives next to hydrothermal vents, is Relicanthus daphneae.

Relicanthus daphneae is a classic example of convergent evolution, the independent evolution of similar features in species of different lineages.

"Even though this animal looks very much like a sea anemone, it is not one," Rodríguez said. "Both groups of animals lack the same characters, but our research shows that while the anemones lost those characters over millions of years of evolution, R. daphneae never had them. Putting these animals in the same group would be like classifying worms and snakes together because neither have legs."

For now, Relicanthus daphneae is the only species in the new order, but researchers hope to change that. "Although we've long known about the existence of this giant animal, it's only in recent years that we're really starting to understand where it fits into the tree of life," Rodríguez said. "So imagine what else is still out there to discover."

American Museum of Natural History. "New order of marine creatures discovered among sea anemones." ScienceDaily. ScienceDaily, 7 May 2014. <www.sciencedaily.com/releases/2014/05/140507212257.htm>.

American Museum of Natural History. (2014, May 7). New order of marine creatures discovered among sea anemones. ScienceDaily. Retrieved March 3, 2015 from www.sciencedaily.com/releases/2014/05/140507212257.htm

American Museum of Natural History. "New order of marine creatures discovered among sea anemones." ScienceDaily. www.sciencedaily.com/releases/2014/05/140507212257.htm (accessed March 3, 2015).

More From ScienceDaily

More Plants & Animals News

Featured Research

Mar. 3, 2015 — New assays can detect malaria parasites in human blood at very low levels and might be helpful in the campaign to eradicate malaria, reports a new study. An international team led by Ingrid Felger, ... full story

Mar. 3, 2015 — While studying a ground-nesting bird population near El Reno, Okla., a research team found that stress during a severe weather outbreak of May 31, 2013, had manifested itself into malformations in ... full story

Mar. 3, 2015 — The 3-D printing scene, a growing favorite of do-it-yourselfers, has spread to the study of plasma physics. With a series of experiments, researchers have found that 3-D printers can be an important ... full story

Mar. 3, 2015 — Most people consume more salt than they need and therefore have a higher risk of heart disease and stroke, which are the two leading causes of death worldwide. But a new study reveals that dietary ... full story

Mar. 3, 2015 — By examining the forces that the segments of mosquito legs generate against a water surface, researchers have unraveled the mechanical logic that allows the mosquitoes to walk on water, which may ... full story

Mar. 3, 2015 — Pediatric otolaryngologists and surgeons are concerned with parents getting the wrong message regarding the safety/desirability of letting babies and young children eat peanuts to prevent them from ... full story

Mar. 3, 2015 — Researchers have developed a new way of rapidly screening yeasts that could help produce more sustainable biofuels. The new technique could also be a boon in the search for new ways of deriving ... full story

Mar. 3, 2015 — Similar to humans and animals, plants possess an innate immune system that protects them from invading pathogens. Molecular structures that only occur in pathogens enable their recognition and ... full story

Mar. 3, 2015 — For almost a century, scientists have been puzzled by a process that is crucial to much of the life in Earth's oceans: Why does calcium carbonate, the tough material of seashells and corals, ... full story

Featured Videos

Rare Goblin Shark Found in Australia

AFP (Mar. 3, 2015) — A goblin shark, a rare sea creature described as an &apos;alien of the deep&apos; is found off Australia and delivered to the Australian Museum in Sydney. Duration: 01:25
Video provided by AFP

Zookeepers Copy Animal Poses In Hilarious Viral Photos

Buzz60 (Mar. 2, 2015) — Zookeepers at the Symbio Wildlife Park in Helensburgh, Australia decided to take some of their favorite animal photos and recreate them by posing just like the animals. Jen Markham (@jenmarkham) has the story.
Video provided by Buzz60

Related Stories

Feb. 16, 2015 — New research shows that a burst of evolutionary innovation in the genes responsible for electrical communication among nerve cells in our brains occurred over 600 million years ago in a common ... full story

Jan. 12, 2015 — Advanced photographic tools in an unmanned Autonomous Underwater Vehicle (AUV) have been used to make major advancements in estimating deep-sea ecosystem diversity at ‘landscape’ scales, ... full story

Dec. 1, 2014 — A research group has revealed how a seemingly simple animal is able to produce nerve cells throughout its entire body. The study shows that the stem cells that a sea anemone uses to generate its ... full story

Feb. 20, 2013 — A research group has shed new light on the evolutionary origin of the head. Scientists show that in a simple, brainless sea anemone, the same genes that control head development in higher animals ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.